Last fall, on Nov. 13, more than 200 activists protested on Capitol Hill, demanding a Green New Deal — a massive economic stimulus package designed to create jobs, remake the U.S. energy system and fight climate change. Rep.-elect Alexandria Ocasio-Cortez, D-N.Y., waded into their midst, vaulting the movement to national prominence. As determined young protesters in matching brown T-shirts hunkered in front of the unoccupied desk of Rep. Nancy Pelosi, D-Calif., holding signs reading “Step Up or Step Aside” and “Green Jobs for All,” Ocasio-Cortez addressed them.

“I just want to let you all know how proud I am of each and every single one of you for putting yourselves and your bodies and everything on the line to save our planet, our generation and our future,” she said, as cameras rolled. Indeed, by day’s end, many protesters were arrested.

The Green New Deal is popular: According to a recent poll by Yale University and George Mason University, more than 80 percent of registered voters support the concept. But it’s also vague about details, and Democratic leaders are divided on how to respond. Even as newly elected progressives and activists push for sweeping policy change, the party’s established powerbrokers favor caution. How the party resolves this discord could determine whether climate change becomes a prominent issue in the 2020 elections — and what action Democrats are prepared to take on it, should their power expand.

efore taking office, Ocasio-Cortez pressed Pelosi to create a Green New Deal select committee, which would have one year to design a job-creating solution to climate change. Ocasio-Cortez’s proposal — crafted in partnership with the Sunrise Movement and Justice Democrats, a progressive political action committee working to get corporate money out of politics — calls the transition away from fossil fuels “a historic opportunity to virtually eliminate poverty in the United States.” A Green New Deal would include job training programs in renewable energy and guaranteed employment for all Americans.

“Climate change is an urgent issue,” said Rep. Deb Haaland, D-N.M., who campaigned on getting the country to 100 percent renewable energy and was an early supporter of the Green New Deal. “We have to do something now.”

The Green New Deal’s massive scope and ambition — to wean the entire country from fossil fuels in just over a decade — comes in response to scientists’ ever more urgent warnings. According to the Intergovernmental Panel on Climate Change, nations must reduce greenhouse gas emissions to net-zero by 2050, or face increasingly catastrophic consequences. Yet the politics of climate change remain fraught — even among Democrats.

Democratic House leaders firmly rejected Ocasio-Cortez’s proposal for a select committee. According to E&E News, the Democratic chairs of existing committees bristled at the possibility of a new select committee usurping some of their own powers. Instead, House Speaker Pelosi reinstated the defunct Climate Crisis Select Committee, which is charged with investigating and recommending climate change solutions. However, it lacks authority to craft legislation, and its members will be allowed to accept campaign donations from the fossil fuel industry, something Ocasio-Cortez wanted to ban.

“The title is the only thing about the committee that begins to acknowledge the magnitude and urgency of the crisis we are in,” said Benjamin Finegan, an organizer with the Sunrise Movement.

University of Oregon law professor Greg Dotson, who worked on climate policy for former Rep. Henry Waxman, D-Calif., believes the party’s internal disagreement is a symptom of the growing pains it’s experiencing as it regains power. “We are in an interesting situation where the Democratic Party agrees on the most important things, which are climate change is happening, it’s caused by humans, and we have to take action to address it,” Dotson said. “Because they’re coming out of the minority, how exactly to do that, they’re still working on.”

Although the Green New Deal select committee would have a new and specific mission, there are other ways to advance its goals. Democrats on House committees like Transportation and Energy and Environment have expertise on key climate issues, and could do similar work. “Advocates should understand that there’s a tremendous amount of institutional history and expertise on all the committees,” for even the most far-reaching goals of a Green New Deal, Dotson said.

But a new generation of climate change activists, including Finegan, dismisses the idea that the existing power structure can address the climate crisis. “I think that argument is politicians being politicians,” Finegan said. After all, for decades, politicians have known climate change was happening, but they’ve done little to stop it. It’s a frustration with the old guard that some early-career Democrats, like Ocasio-Cortez and Haaland, seem to share. “We should have done something decades ago,” Haaland said.

To be clear, even if a new committee were created, Green New Deal legislation would have a snowball’s chance in Phoenix of passing the Republican-controlled Senate, never mind being signed into law by President Donald J. Trump. Still, the debate matters: “For the next two years, the most successful outcome would be for the Democratic Party to come to a view on how to address climate change and the equity issues that the Green New Deal points to,” Dotson said.

The sooner that happens, the better. Leadership has never been more needed: In 2018, after years of decline, carbon dioxide emissions again surged in the United States, even as climate change’s impacts became harder to ignore.

Maya Kapoor is an associate editor at High Country News, overseeing California, the American Southwest, the U.S.-Mexico Borderlands and the Southern Rockies. Email her at mayak@hcn.org or submit a letter to the editor.